ALPHA          =  %x41-5A / %x61-7A   ; A-Z / a-z
BIT            =  "0" / "1"
CHAR           =  %x01-7F                    ; any 7-bit US-ASCII character,                    ;  excluding NULCR             =  %x0D                    ; carriage returnCRLF           =  CR LF                    ; Internet standard newlineCTL            =  %x00-1F / %x7F                    ; controlsDIGIT          =  %x30-39                    ; 0-9DQUOTE         =  %x22                    ; " (Double Quote)HEXDIG         =  DIGIT / "A" / "B" / "C" / "D" / "E" / "F"HTAB           =  %x09                    ; horizontal tabLF             =  %x0A                    ; linefeedLWSP           =  *(WSP / CRLF WSP)                    ; linear white space (past newline)OCTET          =  %x00-FF                    ; 8 bits of dataSP             =  %x20VCHAR          =  %x21-7E                    ; visible (printing) charactersWSP            =  SP / HTAB                    ; white space